Synchrotron WAXS and XANES studies of silica (SiO2) powders synthesized from Indonesian natural sands

International Conference on Science and Applied Science (Engineering and Educational Science) 2016

物理学;工业技术;教育

Muchlis, Khairanissa^1 ; Fauziyah, Nur Aini^1 ; Soontaranon, Siriwat^2 ; Limpirat, Wanwisa^2 ; Pratapa, Suminar^1

Department of Physics, Faculty of Mathematics and Natural Sciences, Institute of Technology Sepuluh Nopember (ITS), Surabaya

60111, Indonesia^1

Synchroton Light Research Institute (Public Organization), Nakhon Ratchasima, Thailand^2

关键词: Amorphous phase;    Edge features;    Energy ranges;    Purification process;    Research institutes;    Synchrotron light;    X-ray absorption near edge spectroscopy;    XANES spectra;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/795/1/012007/pdf
DOI  :  10.1088/1742-6596/795/1/012007

来源: IOP

【 摘 要 】

In this study, we have investigated polymorphic silica (SiO2) powders using, Wide Angle X-ray Scattering (WAXS) and X-Ray Absorption Near Edge Spectroscopy (XANES), laboratory X-Ray Diffraction (XRD) instruments. The WAXS and XANES spectra were collected using synchrotron radiation at Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima, Thailand. The silica powders were obtained by processing silica sand from Tanah Laut, South Kalimantan, Indonesia. Purification process of silica sand was done by magnetic separation and immersion with HCl. The purification step was needed to reduce impurity or undesirable non Si elements. Three polymorphs of silica were produced, i.e. amorphous phase (A), quartz (B), and cristobalite (C). WAXS profile for each phase was presented in terms of intensity vs. 2θ prior to analyses. Both XRD (λCuKα=1.54056 Å) and WAXS (λ=1.09 Å) patttern show that (1) A sample contains no crystallites, (2) B sample is monophasic, contains only quartz, and (3) C sample contains cristobalite and trydimite. XRD quantitative analysis using Rietica gave 98,8 wt% cristobalite, while the associated WAXS data provided 98.7 wt% cristobalite. Si K-edge XANES spectra were measured at energy range 1840 to 1920 eV. Qualitatively, the pre-edge and edge features for all phases are similar, but their main peaks in the post-edge region are different.